A. Field of the Invention
This invention generally relates to vehicle tires and, more particularly, to directional winter vehicle tires having a tread design that enhances braking and acceleration in snow.
B. Description of Related Art
It is well known to provide tires with various tread designs to improve the performance of vehicles that use the tires. Some tires are especially designed for use in winter, and thus have tread features that improve the tire's (and thus the vehicle's) performance on snow, ice and the like.
To improve a tire's performance, it is known to provide a tread with circumferential ribs having non-planar side walls. U.S. Pat. No. 6,250,354, for example, discloses a tire tread having a central circumferential groove formed by circumferential ribs having corrugated sides. The corrugated sides are formed by furrows and ridges having walls of equal length. U.S. Pat. No. 6,986,372 discloses a tire tread having a pair of outer circumferential grooves formed by circumferential ribs having sides with serrations. The serrations are on angled portions of the sides and are formed by walls of equal length. Publication No. US 2007/0240801 discloses a tire tread having circumferential grooves formed by circumferential ribs having sides with a zigzag shape. The zigzag shape is formed by edges having a step shape in the circumferential direction.
This invention, in one embodiment, discloses a tire tread having at least one circumferential groove formed by circumferential ribs having sides with radially extending paddles that are significantly different than known designs. The orientation of the circumferential groove as well as the overall tread design may also be significantly different from known tire tread designs. As a result, this invention provides a vehicle tire with improved performance, especially as a winter tire, over known tires.